$<?
$total_t_tax_porc=(($total_t*'8.25')/'100');
$total_t_d_tax_porc= substr($total_t_tax_porc, 0, strlen($total_t_tax_porc) -2);
$total_t_c_tax_porc= substr($total_t_tax_porc, -2, 2);
echo $total_t_d_tax_porc.','.$total_t_c_tax_porc;
?>.

&nbsp;$<?
$total_t_tax=($total_t+$total_t_tax_porc);
$total_t_d_tax= substr($total_t_tax, 0, strlen($total_t_tax) -2);
$total_t_c_tax= substr($total_t_tax, -2, 2);
echo $total_t_d_tax.','.$total_t_c_tax;
$_SESSION[total_t]=$total_t_tax;
?>.

javascript: validar(document.getElementById('datos'));

document.datos.action='acciones/sumo_impuestos.php'; document.datos.submit()